Electrical oven cooking and cleaning control system

ABSTRACT

This disclosure relates to a control system for an electrical oven that permits the broil and bake heaters thereof to not only be utilized for normal cooking operations, but also for an ovencleaning operation wherein the temperature of the oven is elevated to burn off the undesirable cooking soil and the like, the control means operating the bake heater at substantially full rated power and the broil heater at part rated power in a parallel relation thereof when the control means is set for a cleaning operation and the oven is below the cleaning temperature while operating both of the bake and broil heaters at part rated power thereof in a series relation thereof when the temperature of the oven is above the cleaning temperature.

United States Patent Inventor Siegh'ied E. Maneeke Indiana, Pa.

Appl. No. 699,433

Filed Jan. 22, 1968 Patented July 6, 1971 Assignee Robertshaw Controls Company Richmond, Va.

ELECTRICAL OVEN COOKING AND CLEANING CONTROL SYSTEM 3,413,444 11/1968 Heit 3,358,122 12/1967 Torrey ABSTRACT: This disclosure relates to a control system for an electrical oven that permits the broil and bake heaters thereof to not only be utilized for normal cooking operations, but also for an oven-eleaning operation wherein the temperature of the oven is elevated to burn ofi the undesirable cooking soil and the like, the control means operating the bake heater at substantially full rated power and the broil heater at part rated power in a parallel relation thereof when the control means is set for a cleaning operation and the oven is below the cleaning temperature while operating both of the bake and broil heaters at part rated power thereof in a series relation thereof 'when the temperature of the oven is above the cleaning temperature.

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INVENTOR SIEGFRIED E. MANECKE BROIL POSITION HIS ATTORNEYS PATENTED JUL 6197! SHEET l [1F 4 E w w m M b WA 2 mm L a 4 9 42 w o l 2 73 L mm 3 F a m an 5% m is w w 7 m E s I 4 3 8 /6 2 P 6 2 5 L E III 3 B U I M M 1 Ll R T l U B 9 B Y 3 E 8 6 B m E 3 8 m I 6 II a m B 4 44 7 K N 0. mm a w 6 w m a k (1 G 5 Q 3M0 6 FW 2 M a 6 6 N 6 5 A 4 48 69 E 33 3 O Q mm F 2 5 W T I}- 6 6 7 5 3 4 3 8 O 2 a 6 A k r/ 7N 2 HIS ATTORNEYS ELECTRICAL OVEN COOKING AND CLEANING CONTROL SYSTEM cally cleaned. It is also well known that such a cleaning operation can be accomplished by elevating the temperature in the oven well above the normal high temperature cooking operation, such as the conventional 625 F., to around 950 F. for an extended period of time, such as for two hours, whereby the cooking soil will be burned off and can be expelled from the oven in the form ofsmoke and the like.

Accordingly, it is a feature of this invention to provide an improved control system for such an electrical oven wherein the control system will provide for the normal cooking operations of the oven as well as a high temperature-cleaning opera tion thereof in an improved manner.

In particular, the embodiment of this invention comprises a control system for an electrical oven having a bake heater and a broil heater, the control means being adapted to operate the bake heater at substantially full rated power thereof and operate the broil heater at part rated power thereof in a parallel relation when the control means is set for a cleaning operation and the temperature of the oven is below the cleaning temperature whereas the control means will operate both of the bake and broil heaters at part rated power thereof in a series relation thereof when the temperature of the oven is above the cleaning temperature so as to provide a relatively narrow temperature differential in the oven relative to the predetermined cleaning temperature thereof for a more effective and efficient cleaning operation.

Accordingly, it is an object of this invention to provide an improved control system for an electrical oven or the like, the control system of this invention having one or more of the novel features set forth above or thereinafter shown or described.

Other objects, uses, and advantages of this invention are apparent from a reading of this description which proceeds with reference to the accompanying drawing wherein:

FIG. 1 illustrates the control system of this invention in schematic form with the system in its normal off condition.

FIG. 2 is a view similar to FIG. 1 and illustrates the control system in its Bake" condition.

FIG, 3 is a view similar to FIG. 1 and illustrates the control system in its Broil" condition.

FIG. 4 is a view similar to FIG. 1 and illustrates the control system in its oven "Cleaning" condition.

While the various features of this invention are hereinafter described and illustrated as being particularly adaptable for providing a cooking and cleaning control system for an electrical oven having certain specifically described features, it is to be understood that the features of this invention can be utilized singly or in any combination thereof to provide a control system for other types of electrical ovens or the like.

Therefore, this invention is not to be limited to only the em bodiment illustrated in the drawings, because the drawing is merely utilized to illustrate one of the wide variety of the uses of this invention.

Referring now to FIG. 1 of the drawings, the electrical oven cooking and cleaning control system of this invention is generally indicated by the reference numeral 10 and comprises a conventional oven broil heater or element 11 and a conventional bake heater of element 12 electrically interconnected in the control system 10 of this invention in a manner hereinafter described.

The power source provided for the control system 10 is a conventional three wire power source comprising a neutral line N and two power-lines L and L, whereby the power source for the control system 10 can supply voltages of 220 volts and/or 1 10 volts as will be apparent hereinafter.

A first thermostatically operated electrical switch 13 is provided for the control system 10 and has a thermostatically operated switchblade l4 electrically interconnected to the power source lead L, by a lead 15 and is adapted to close against a contact 16 as long as the thermostatically operated switch 13 senses a temperature in the oven below a predetermined cleaning temperature, such as 950 F., regardless of whether the control system 10 is set for a cleaning operation, a cooking operation, etc.

The contact 16 is interconnected to a timer operated switchblade 17 by a lead 18. the timer-operated switchblade 17 normally being disposed in its closed position against an electrical contact 19 by a timer motor 20 that operates a conventional clock for the cooking apparatus containing the control system 10.

In particular, the timer motor 20 is placed across the power source line L and the neutral line N by having one side 21 thereof electrically interconnected by a lead 22 to a lead 23 that is interconnected to the neutral line N. The other side 24 of the timer motor 20 is electrically connected by a lead 25 to a lead 26 is interconnected to the power source line L,.

The power source line 26 is also interconnected to a switchblade 27 of another electrical switch that is operated by the timer motor 20 so as to be normally disposed in a closed position against a contact 28.

However, the timer motor 20 is of the conventional type that can be set by the housewife or the like to automatically provide a normal cooking operation in the oven for a predetermined length of time so that after the lapse of such preselected length of cooking time, the switchblades 17 and 27 will be moved by the timer motor 20 to the opened position as illustrated in the drawing to terminate the operation of the bake and/or broil heaters 12 and 11 in a conventional manner. The switchblades remain in their thus opened condition until the housewife or the like sets the clock back to its normal manual position so that the blades 17 and 27 will be in their closed condition as illustrated in FIG. 2. However, the clock motor means 20 does not form a part of this invention other than illustrating how the features of this invention can be utilized in combination with an automatic cooking operation.

The contact 19 is interconnected by a lead 29 to a bridging contact member 30 of a second thermostatically operated electrical switch 31 that is adapted to be, manually adjusted by the housewife or the like from its off" position to any desired cooking temperature position so that the bridging contact member 30 will only close against a pair of contacts 32 and 33 when the thermostatically operated switch 31 senses a temperature below the selected cooking temperature and will move the contact member 30 away from the contacts 32 and 33 when sensing a temperature in the oven above the selected cooking temperature. Of course, when the thermostatically operated electrical switch 31 is disposed in its off" position, the bridging contact member 30 is held out of electrical contact with the contacts 32 and 33 regardless ofthe temperature in the oven.

The manual selector means for the thermostatically operated switch 31 is so constructed and arranged in a manner well known in the art that the same controls another electrical switch construction generally indicated by the reference numeral 34 depending upon the setting of the manual selector means for the thermostatically operated switch 31. For example, when the thermostatically operated switch construction 31 is disposed in its off position, a pair of switchblades 35 and 36 of the switch construction 34 are disposed in the position illustrated in FIG. 1. However, when the electrical switch 31 is disposed in any baking temperature position thereof, the switchblades 35 and 36 are respectively disposed against contacts 38 and 40 as illustrated in FIG. 2 for a purpose hereinafter described and when the thermostatically operated switch 31 is disposed in its broil position, the switchblades 35 and 36 are respectively disposed against contacts 37 and 39 as illustrated in FIG. 3.

Thus, it can be seen that one manual selector switch can be provided for the control system 10 to not only set the thermostatically operated electrical switch 31 at a desired cooking temperature setting thereof, but also to set the electrical switch 34 for a purpose hereinafter described.

Another manually operated selector switch is provided for the control system 10 and will operate a first pair of cooperating switchblades 41 and 42, a second pair of cooperating switchblades 43 and 44, as well as switch blades 45, 46 and 47 in a manner hereinafter described.

When such second selector switch is disposed in its oven" position the switchblades 41-47 are all disposed in the position illustrated in FIGS. l--3 whereby the switchblade 43 is against a contact 48, the switchblade 44 is against a contact 49, the switchblade 45 is against a contact 50, and the switchblade 46 is against a contact 51.

However, when the second selector switch is set in its oven cleaning" position as illustrated in FIG. 4 in a manner hereinafter described, the switchblade 41 is disposed against a contact 53, the switchblade 43 is moved away from the contact 48 and is disposed against a contact 54, the switchblade 44 is moved away from the contact 49 and is disposed against a contact 55, the switchblade 45 is moved away from the contact 50 and is disposed against a contact 56, the switchblade 46 is moved away from the contact 51 and is disposed against a contact 57, and the switchblade 47 is moved against a contact 58 for a purpose hereinafter described.

The switchblade 35 of the electrical switch 34 is directly interconnected to the lead 23 of the neutral line N while the lead 23 is also interconnected to the contact 54 by a lead 59. The other switchblade 36 of the electrical switch 34 is interconnected by a lead 60 to a lead 61 that is interconnected to the contact 28 for the timer-operated switchblade 27 as well as to the contact 55, the lead 61 having a bimetal pulser 62 therein that will electrically disconnect the contact 28 from the contact 55 for a momentary period of time and then electrically interconnect the contact 28 with the contact 55 for another momentary period of time in a cycling manner so as to cycle 'the electrical connection between the contacts 28 and 55 when the electrical current is permitted to flow through the lead 61 in a cleaning" setting of the system 10 for a purpose hereinafter described.

Similarly, the contact 38 of the electrical switch 34 is interconnected to the contact 48 by a lead 63 that has an adjustable bimetal pulser 64 therein that is adapted to cycle the electrical connection between the contacts 38 and 48 when electrical current is supplied through the lead 53 in a broil setting of the system 10 in a manner hereinafter described.

Since the bimetal pulser 64 is utilized in connection with the broil heater 11 in a manner hereinafter described, the pulser 64 can be manually adjusted by the housewife or the like so as to electrically interconnect the contact 38 with the contact 48 anywhere from 50 percent of the time to 100 percent of the time when electrical current is supplied through the lead 63, such selection feature controlling the rare to well-done condition of meat during a broiling operation. In contrast, the bimetal pulser 62 in the line 61 has been previously set at the factory so as to electrically interconnect the contact 28 with the contact 55 approximately 50 percent of the time the electrical current is supplied through the lead 61 for a cleaning operation as will be apparent hereinafter in order to prevent the oven from heating up too fast and to prevent the soil in the oven from being burned off too fast during the cleaning operation.

The contact 37 of the electrical switch 34 is not electrically interconnected to any other part of the control system 10 whereas the contact 39 of the switch 34 is interconnected to the lead 63 by a lead 65. The remaining contact 40 of the electrical switch 34 is interconnected to the contact 49 by a lead 66, the lead 66 also being electrically interconnected to the contact 51 by a lead 67.

The switchblade 43 is electrically interconnected to one side 68 of the broil heater or element 11 by a lead 69 while the switchblade 44 is interconnected to the side 70 of the bake heater or element 12 by a lead 71. The other side 72 of the broil heater or element 1 1 is interconnected to the contact 52 by a lead 73 and the lead 73 is, in turn, interconnected to the contact 32 by a lead 74. The other side 75' of the baker heater or element 12 is interconnected to the contact 53 by a lead 75 which, in turn, is interconnected to the contact 33 by a lead 76.

The switchblade 41 is electricallyinterconnected to the switchblade 42 by a lead 77 and the lead 77 is, in turn, interconnected to a contact 78 by a lead 79. The contact 78 cooperates with a contact 80 interconnected to the lead 29 by a lead 81 so as to form part of a thermostatic safety switch that will have a switchblade or bridging member 82 thereof moved out of normal bridging contact with the contacts 80 and 78 when a fan motor 83 ceases to function properly during a cleaning operation of the oven. For example, the fan motor 83 must be functioning properly to prevent the outside casing or frame of the cooking apparatus form exceeding a predetermined safe temperature, such as 194 F. or the like, during a cleaning operation. Such fan cooling means is conventional in the art and need not be further described. Therefore, as long as the fan motor 83 is functioning properly, the bridging member 82 bridges the contacts 78 and 80. However, should the fan motor 83 not be functioning properly so as to cause an overheating of the cooking apparatus casing or frame, such overheating will thermostatically cause the bridging member 82 to move out of electrical contact with the contacts 78 and 80 to terminate the cleaning operation until the bridging member 82 again bridges the contacts 78 and 80 as will be apparent hereinafter.

One side 84 of the fan motor 83 is interconnected by a lead 85 to the neutral line lead 23. The other side 86 of the fan motor 83 is interconnected by a lead 87 to the contact 56, the lead 87 being interconnected to one side 88 of a resistor 89 by a lead 90. The other side 91 of the resistor 89 is interconnected by a lead 92 to one side 93 of a neon bulb 94 that will be energized only during a cleaning cycle to indicate that the oven is above 550 F. in a manner and for a purpose hereinafter described. The other side 95 of the neon bulb 94 is interconnected by a lead 96 to a lead 97.

The lead 97 is interconnected to one contact 98 of an electrical switch 99 that is thermostatically controlled by a thermostatic sensing means of the thermostatically operated electrical switch 13 previously described so as to control a switchblade or bridging contact member 100 of the electrical switch 99. The contact 98 of the electrical switch ,99 cooperates with a contact 101 that is electrically interconnected to a contact 102 by a lead 103 whereby the bridging member 100 bridges against the contacts 98 and 101 as long as the thermostatic sensing means of the electrical switch 13 senses a temperature in the oven below a safe temperature, such as 550 F., and will be moved away from bridging contact with the contacts 98 and 101 as long as the thermostatic sensing means of the thermostatically operated switch 13 is sensing a temperature in the oven above 550 F. for a purpose hereinafter described. The lead 103 is also electrically interconnected to the lead 92 for a purpose hereinafter described.

An oven door-latching member operated switchblade 104 is provided to cooperate with the contact 102 and is electrically interconnected to the contact 50 by a lead 105. In particular, when an oven door-latching member for the control system 10 is disposed in its unlatched position, suitable mechanical means between the oven door-latching member and the switchblade 104, such as a camming means or the like, maintains the switchblade 104 in its open condition away from the contact 102. However, when the oven door-latch member is partially moved from its unlatched position toward its oven door-latching position, such mechanical interconnection means causes the switchblade 104 to move against the contact 102 and remain against the contact 102 until the door-latch member is subsequently moved to its full latching position.

At the same time that the oven door-latching member is moved from its unlatched position to its oven door-latching position, the previously described selector switch for operating the switchblades 41-47 will be now made accessible to the housewife or the like to change the same from its "oven" position to its clean position for a purpose hereinafter described. Thus, it can be seen that such selector means can not be manipulated by the housewife or the like unless the oven door-latching member is in its latching position.

The lead 97 that is interconnected to the contact 98 of the electrical switch 99 is also interconnected to one side 106 of a solenoid coil 107, the other side 108 of the solenoid coil 107 being interconnected to a contact 109 by a lead 110. The contact 109 forms part of an oven door operated switch 111 that comprises a switchblade l 12 electrically interconnected to the neutral line lead 23 by a lead 113. The switchblade 112 is disposed against the contact 109 as long as the oven door is in a closed position. However, when the oven door is in an open position, the switchblade 112 is moved away from the contact 109 and is disposed against a contact 114 of the switch 111. The contact 114 is electrically interconnected by a lead 115 to one side 116 of an oven lamp 117 while the other side 118 of the indicating lamp or light 117 is interconnected to the power source lead 26 by a lead 119.

Thus, each time the oven door is disposed in its open position, the oven light 117 is energized by being placed across the power source lines N and 1.. by the switchblade 111 to illuminate the oven cavity. However, when the oven door is disposed in its closed position, the switchblade 111 is disposed against the contact 109 so that the oven light 117 will not be energized.

A smoke-eliminating electrical heater or element 120 is provided for the control system and can be disposed in the vent of the oven for a purpose hereinafter described. One side 121 of the smoke eliminating heater or element 120 is interconnected by a lead 122 to the switchblade 46 while the other side 123 thereof is interconnected to the neutral lead 23 by a lead 124.

A timer motor 125 is provided for the control system 10 to control the time period for a cleaning operation of the oven and has one side 126 interconnected by a lead 127 to the contact 58 while the other side 128 thereof is interconnected to the neutral lead 23 by a lead 129. The lead 127 is interconnected by a lead 130 to one side 131 ofa neon bulb 132 that has its other side 133 interconnected by a lead 134 to the neutral lead 23.

As will be apparent hereinafter, the neon light 132 will be energized during the entire oven cleaning cycle so as to indicate the the housewife or the like that the cleaning cycle is continuing to operate or has been terminated.

If desired, the controlsystem 10 can include a conventional plug-in outlet receptacle 135 having one side 136 thereof interconnected by a lead 137 to the power source lead 26 while the other side 138 is interconnected by a lead 139 to the neutral lead 23, the lead 137 having a conventional fuse 140 therein whereby the outlet receptacle 135 provides a 110 volt outlet receptacle by always being, in effect, placed across the powerline L, and the neutral line N.

The operation of the control system 10 of this invention will now be described in connection with a typical baking opera tion thereof, a broiling operation thereof, and an oven-cleaning operation thereof.

BAKING OPERATION As illustrated in FIG. 2, the control system 10 of this invention has been set in a selected bake position thereof by the selector means of the thermostatically operated switch 31 whereby the system 10 is electrically energized as illustrated by the bold lines in FIG. 2 as long as the thermostatically operated switch 31 is sensing a temperature in the oven below the selected baking temperature so as to hold the contact member 30 in bridging contact against the contacts 32 and 33.

In particular, thesetting of the thermostatic switch 31 in a particular baking position thereof, causes the switchblades 35 and 36 to respectively move against the contacts 38 and 40 and since the timer-operated switchblades 17 and 27 are normally disposed in their closed position as illustrated in FIG. 2, and since the thermostatic switch construction 13 only opens the switchblade 14 when the thermostatic which construction 13 senses a temperature above the high cleaning temperature, such as 950 F., the bake heater or element 12 is placed across the power lines L and L so as to be operated at substantially full rated power thereof and the broil element or heater 11 is placed across the source line L and neutral line N so as to be operated at part rated power thereof. Sincethe contact member 30 of the thermostatically operated switch 31 is always interconnected to the power source line L; in any bakesetting position thereof, the broil heater 11 and the bake heater 12 are in parallel relationship except that the bake heater 12 is operated at substantially its full-rated power and the broiler element 11 is operated at part of its rated power.

When the thermostatically operated switch construction 31 senses that the temperature in the oven has risen above the preselected bake temperature, the bridging member 30 is moved out of electrical contact with the contacts 32 and 33 so as to temporarily terminate the operation of the broil and bake heaters 11 and 12 until the temperature in the oven decreases to or falls slightly below the selected temperature whereby the thermostatically operated switch construction 31 will again place the bridging member 30 against the contacts 32 and 33.

Thus, the control systems 10 in any baking position will cycle the broil and bake heaters 11 and 12 between their onand-off conditions as described above so as to tend to maintain the temperature in the oven at the selected baking temperature.

Since the switchblade 46 is normally disposed against the contact 51, during any cooking operation of the control system 10, the smoke eliminator heater is continuously energized in any selected bake position thereof because the same is placed across the power source line L, by the blade 36 and the neutral line N in parallel relation with the bake heater or element 12.

BROILING OPERATION When the housewife or the like desires to utilize the control system 10 to perform a broiling operation, the housewife or the like turns the selector means of the thermostatically operated switch construction 31 to its broil" position whereby not only is the thermostatically operated switch construction 31 now set to operate the bridging member 30 so as to tend to maintain a temperature in the oven of approximately 625 F., or other conventional broiling temperature, but also the switchblade 35 and 36 are set in the position illustrated in FIG. 3 whereby the switchblade 35 is disposed against the dead ended contact 37 and the switchblade 36 is disposed against the contact 39.

Since during a normal cooking operation of the control system 10 the timer operated switchblade 17 and 27 are disposed in their closed position and the switchblade 14 of the thermostatically operated switch 13 is disposed in its closed position, the broil heater or element 11 is placed directly across the power source lines L, and L as long as the thermostatically operated electrical switch 31 is sensing a tempera ture in the oven below the selected broil temperature so as to maintain the bridging contact 30 against the contacts 32 and 33.

However, it is to be understood that it the bimetal pulser 64 utilized in the control system 10 as illustrated, such bimetal pulser 64 would be manually adjusted by the housewife or the like to provide the desired degree of time that the contact 39 will be electrically interconnected to the contact 48 to energize the broil heater 11 in relation to the time that the bimetal pulser 64 disconnects the contact 38 from the contact 48 in cycling so as to control the broil heater 11 in a cycling manner not connected with the cycling operation of the thermostatically operated switch 31. In this manner, the housewife or the like can preselect the desired degree of doneness" of the meat or the like being broiled in relation to the surface degree of doneness" thereof.

In the broil position of the control system 10 as illustrated in FIG. 3, it can be seen that the smoke heater 120 and bake heater 12 are placed in series across the neutral line N and the power source line L, in a parallel relation with the broil heater 11 when the bridging contact member 30 of the thermostaticallyoperated switch construction 31 is disposed against the bridging contacts 32 and 33.

However, since the smoke heater 120 and bake heater 12 are in series during the broiling operation .of the control system 10, the effect of the bake heater 12 on the broiling operation is substantially negligible while the effect of the smoke heater 120 is to tend to eliminate smoke passing through the oven vent.

However, it is also to be understood that if it is desired that the smoke eliminator heater 120 is not to be operative during the aforementioned baking operation or broiling operation of the control system 10, the lead 67 can be eliminated from the control system 10 so that the contact 51 will be a dead ended contact whereby the smoke eliminator heater 120 would still function in the system 10 of this invention during the cleaning operation thereof now to be described, but not during the previously described baking and broiling operations.

CLEANING OPERATION When the housewife or the like desired to effect a cleaning operation of the control system 10, it will be assumed that the control system 10 is in the off" position, as illustrated in FIG. 1.

In order for the housewife or the like to initiate the cleaning operation, the housewife or the like must initially move the oven door-latching member from its unlatched position toward its oven door-latching position and as the doorlatching member is so partially moved, a mechanical interconnection, such as a cam means or the like, closes the switchblade 104 against the contact 102 and since the oven door is in its closed position to maintain the switchblade 112 against the contact 109 and since the temperature-in the oven is below 550 F. so that the thermostatically operated switch construction 13 is maintaining the bridging member 100 is bridging contact with the contacts 98 and 101, as illustrated in FIG. 1, the solenoid coil 107 is placed across the power source line L and neutral line N so as tobe fully energized and move a latch pin away from the door-latchingimember so that the door-latching member can then be moved to its full latching position. Asthe door-latch member is now moved to its full oven door-latching position, the mechanical interconnection means between the door-latch member and the switchblade 104 causes the switchblade 104 to move back to its open position, whereby the solenoid coil 107 is deencrgized so that the latch pin is again moved to its latching position whereby the door-latching member can only be moved to its unlatching position when the solenoid coil 107 is again energized to retract the latch pin from its latching position.

With the oven door-latching member now in its fully latched position, the selector means for setting a cleaning operation is now exposed to view and is accessible to the housewife or the like to manually move the same from its "off" position to its cleaning cycle start position, such movement of this selector lustrated by bold lines in FIG. 4 as long as the thermostatically operated electrical switch 13 is sensing a temperature in the oven below the cleaning temperature, such as 950 F. to maintain the switchblade 14 against the contact 16, as illustrated in FIG. 4.

' Thus, as long as the thermostatic switch construction 13 is sensing a temperature in the oven below the cleaning temperature, the bake heater 12 is placed across the power source lines L, and L to be operated at substantially full-rated power thereof while the broil heater 11 is disposed in parallel relation with the bake heater 12 and is disposed across the powerline L, and neutral line N so as to be operated at part of its rated power.

Of course, if the bimetal pulser 62 is utilized in the lead 61 in the control system 10, as illustrated, such bimetal pulser will pulsate between its opened and closed positions thereof to cycle the electrical interconnection between the contacts 28 and 55 so as to pulsate the on" and "off" condition of the bake heater 12 in a cyclic manner not connected with the cyclic operation of the thermostatically operated electrical switch only being when the aforementioned latch pin is in its full latching position so as to prevent a premature setting of the selector switch to its cleaning" position before the oven door latching member is in its full latching position and is so maintained by the latch pin. When the housewife or the like subsequently turns such selector means to its oven clcaning" position, such selector means moves the switchblades 41 and 42 against the contacts 52 and 53, moves the switchblades 43 and 44 against the respective contacts 54 and 55, the switchblade 45 against the contact 56, the switchblade 46 against the contact 57 and the switchblade 47 against the contest 58, whereby the system 10 is energized lathe manner il= switch 13.

When the temperature in the oven reaches or exceeds the predetermined cleaning temperature setting of the thermostatic switch construction 13, the thermostatic switch construction 13 will open the switchblade 14 to disconnect the power source line L, from the broil and bake heaters 11 and 12. However, when the switchblade 14 is disposed in its open position, it can be seen that the broil heater '11 and bake heater 12 are disposed in series across the power source line L and neutral line N through the closed switch blades 41 and 42 so that the broil heater 1] and bake heater 12 will be operated at part-rated power as the oven cools down to the preselected cleaning temperature or slightly below the same. At this temperature the switchblade 14 again closes so that the bake heater 12 is operated at substantially its full-rated power and the broil heater 11 is operated at part of its rated power.

Thus, the thermostatic switch 13 will cycle the bake and broil heaters 11 and 12 between the two previously described conditions thereof to tend to maintain the temperature in the oven at the preselected cleaning temperature with the aforementioned narrow temperature differential.

The control system 10 in the cleaning position illustrated in FIG. 4 also has the smoke eliminator heater 120 thereof continuousiy placed across the power source line L and neutral line N during the entire cleaning operation. In addition, the fan motor 83 is placed across the power source iineL, and neutral line N and as long as thesame is functioning properly, the contact bridging member 82 is disposed against the contacts 78and 80.

When the temperature in the oven exceeds a safe temperature, such as 550 F. in the cleaning position thereof, the thermostatically operated switch construction 13 moves the bridging contact member of the electrical switch 99 away from the contacts 98 and 101 so that the solenoid 107 cannot be energized to a condition thereof to retract the latching pin from its latching so that the oven door-latch member could be moved from its oven door latching position to its oven door unlatching position until the contact bridging member 100 again makes contact with the contacts 98 and 101.

Further, since an electrical circuit can be traced between the power source line L and neutral line N in the cleaning position of the control system 10 so as to pass through the resistor 89., neon bulb 94 and solenoid coil 107, the bulb 94 is only energized during the cleaning operation when the temperatures in the oven is above 550 F. to indicate to the housewife or the like that the oven temperature is above a safe temperature for opening the oven door, such as 550 F. In par-' ticular, when the contact member 100 is closed against contacts 101 and 98, the same shunts out bulb 94 so that the bulb 94 cannot be energized at temperatures below 550 F. However, when the contact member 100 moves away from contests 101 and 98 upon the temperature in the oven being above 550 F, the bulb 94 is energised. Even though the sbie= noid coil 107 is in these circuits, the selector switch while in its cleaning position prevents the latch pin from being retracted from its latching position and the resistor 89 prevents full energizing of the solenoid coil [07.

As illustrated in FIG. 4, when the selector means for effecting the aforementioned cleaning operation of the control system is initially moved from its off" position to its cleaning" position, the closing of the switchblade 47 against the contact 58 energizes the cleaning timer motor 125 which will continue to operate for a predetermined period of time after the lapse of which will automatically move the switchblades 41 and 42 to the off position as illustrated in FIG. 1 while moving the selector switch for the cleaning operation to its end of cleaning position. When the blade 47 is moved against the contact 58, the neon bulb 132 is also energized by being placed across the powerline L, and neutral line N so as to indicate that the cleaning cycle is in operation.

When the period of cleaning time has lapsed as set by the cleaning timer motor 125, such as a 2 hour period or the like, the cleaning selector means has been moved by the motor 125 to a position thereof which automatically opens the switchblade 41 and 42 as well as opens the switchblade 47 at the same time as it opens blades 41 and 42 or slightly thereafter.

Since the oven is at approximately 950 F. when the timer motor 125 automatically opens the switchblades 41 and 42, it can be seen that the thermostatically operated switch 13 maintains the bridging member 100 away from the contacts 98 and 101. Also, the indicating lamp 94 remains energized to indicate to the housewife or the like that the oven door cannot be unlatched as the oven is still at an unsafe temperature.

Normally, the housewife leaves the cleaning selector means in the previously described end of cleaning position thereof which occurred after the lapse of the predetermined cleaning time period wherein only the switchblades 41, 42 and 47 were automatically moved to their open position and the switchblades 43, 44, 45 and 46 in their closed position as illustrated in FIG. 4 the opening of the switchblade 47 terminating the operation of the timer motor 125 and the indicating light 132, as well as the operation of the smoke eliminator heater 120, so that the housewife or the like will be visually informed that the cleaning cycle has been terminated without having to look at the selector switch. However, since the light 94 is still energized because the oven is above 550, the housewife does not normally move the oven-cleaning selector switch to its 05" position until the indicating light 94 goes out upon the contact member [00 closing against the contacts 101 and 98 to shunt out the bulb 94 when the temperature in the oven drops to 550 F. or below.

When the safety light 94 goes out or subsequent thereto, the housewife or the like moves the oven selector switch to its "off" position whereby the switchblades 4S and 46 are again moved back against the contacts 51 and 50 and the cleaning selector switch will no longer impede the unlatching of latch in. p With the switchblade 45 now disposed against the contact 50 and with the temperature of the oven now below 550 F., the bridging member 100 has been moved against the contacts 98 and 101 by the temperature-sensing means of the thermostatically operated switch 13 so that the housewife or the like can now begin to move the oven door-latching member from its latched position toward its unlatching position and as the same is being so partially moved, the mechanical interconnection between the switchblade 104 and the door-latching member causes the switchblade 104 to close against the contact 102 and energize the solenoid coil 107 so that the latch pin will be automatically withdrawn from its latching position to permit the door-latching member to move to its fully unlatched position. When the door-latch member is moved to its full-door unlatching position, it can be seen that the mechanical interconnection between the door-latch member and the switchblade 104 again moves the switchblade 104 to its open position so that solenoid 107 is deenergized and the latch pin can move to its latching position and the oven-cleaning selector means will be fully covered by the door-latch member so that the same cannot be operated until the door-latch member is again moved to its door-latched position in the manner previously described.

Of course, if during such unlatching of the oven door after an oven cleaning cycle, the temperature in the oven is above 550' F., the housewife or the like cannot move the doorlatching member from its fully latched position to its fully unlatched position even though she sets the cleaning selector switch in its "off" position because the solenoid coil 107 will not be energized during such partial movement of the oven door-latching member as previously described because the bridging member is maintained away from the contacts 98 and 101 by the temperature-sensing means of the thermostatically operated switchplate 13.

Therefore, it can be seen that this invention provides an improved electrical oven cooking and cleaning control system or the like.

While the form of the invention now preferred has been disclosed as required by the statutes, other forms may be used, all coming within the scope of the claims which follow.

I claim:

1. An electrical oven cooking and cleaning control system comprising a bake heater, a broil heater, an electrical power source, control means having thermostatically operated switch means, and means operatively interconnecting said control means to said power source and said control means to said heaters, said switch means of said control means having a first temperature-sensing condition that interconnects said power source to said heaters for operating said bake heater at substantially full rated power and said broil heater at part rated power when said control means is set for cleaning said oven at a predetermined cleaning temperature and said oven is below said cleaning temperature, said switch means of said control means having a second temperature-sensing condition that interconnects said power source to said heaters for operating both of said bake and broil heaters at part-rated power thereof when the temperature of said oven is above said cleaning temperature.

2. An electrical oven cooking and cleaning control system as set forth in claim ll, said switch means of said control means including a thermostatically operated switch which when closed by sensing a temperature below said cleaning temperature causes said bake heater to operate at said full-rated power and said broil heater to operate at said part rated power, said switch when opened by sensing a temperature above said cleaning temperature causing said bake and broil heaters each to operate at said part rated power thereof.

3. An electrical oven cooking and cleaning control system as set forth in claim 2, said switch causing said bake and broil heaters to be in series relation across said power source when said switch senses a temperature above said cleaning temperature and causing said bake and broil heaters to be in parallel relation across said power source when sensing a temperature below said cleaning temperature.

4. An electrical oven cooking and cleaning control system as set forth in claim 1, a smoke eliminator heater, means operatively interconnecting said control means to said smoke eliminator heater, said control means interconnecting said power source to said smoke eliminator heater for causing operation of said smoke eliminator heater when set in its ovencleaning position. i

5. An electrical oven cooking and cleaning control system as set forth in claim 4, said control means interconnecting said power source to said smoke eliminator heater for causing said smoke eliminator heater to operate during a bake setting thereof and during a broil setting thereof.

6. An electrical oven cooking and cleaning control system comprising a bake heater, a broil heater, a three wire power source comprising a neutral line and two power lines, control means having thermostatically operated switch means and means operatively interconnecting said control means to said power source and said control means to said heaters, said switch means of said control means interconnecting said bake heater across said power lines for substantially full-rated power of said bake heater when said control means is set for cleaning said oven at a predetermined cleaning temperature while interconnecting said broil heater across said neutral line and one of said power lines for approximately one-quarter rated power of said broil heater when the temperature in said oven is below said cleaning temperature, said switch means of said control means interconnecting said bake and broil heaters in series across said neutral line and one of said power lines when the temperature in said oven is above said cleaning temperature to provide approximately one-sixteenth of the rated power of said heaters.

7. An electrical oven cooking and cleaning control system as set forth in claim 6, said broil and bake heaters each having one side thereof electrically interconnected to said one side of the other by an electrical lead, said control means interconnecting one of said powerlines to said electrical lead when said control is set for cleaning said oven and when the temperature in said oven is below said cleaning temperature, said control means disconnecting said one power lead from said electrical lead when said control means is set for cleaning said oven and when the temperature in said oven is above said cleaning temperature.

8. An electrical oven cooking and cleaning control system as set forth in claim 7, said control means interconnecting the other side of said broil heater to said neutral line when set for cleaning said oven and interconnecting the other side of said bake heaterto the other power line when set for cleaning said oven.

9. An electrical oven cooking and cleaning control system as set forth in claim 7, said control means interconnecting said one power line to said electrical lead when set for a bake operation and when the temperature in said oven is below the selected bake temperature, said control means interconnecting the other side of said broil heater to said neutral line and the other side of said bake heater to the other power line when set for said bake operation.

selected broil temperature, said control means interconnecting the other side of said broil heater to the other powerline when set for said broil operation.

11. An electrical oven cooking and cleaning control system as set forth in claim 7, a smoke eliminator heater having one side thereof interconnected to said neutral line, said control means interconnecting the other side of said smoke eliminator heater to one of said powerlines when set for a cleaning operation.

12. An electrical oven cooking and cleaning control system as set forth in claim 11, said control means interconnecting the other side of said smoke eliminator heater to one of said powerlines when said control means is set for a bake operation.

13. An electrical oven cooking and cleaning control system as set forth in claim 12, said control means when set for a bake operation interconnecting the other sides of said bake and smoke eliminator heaters in parallel relation to the same powerline.

14. An electrical oven cooking and cleaning control system as set forth in claim 7, said control means comprising a first thermostatically operated switch that interconnects said one power line to said electrical lead when said control means is set for said cleaning operation and the temperature in said oven is below said cleaning temperature, said control means comprising a second thermostatically operated switch that interconnects said one powerline to said electrical lead when said control means is set for a cooking operation and the temperature in said oven is below the selected cooking temperature, said second switch disconnecting said one powerline from said electrical lead when said con rol means 15 set for a cooking operation and the temperature in said oven is above the selected cooking temperature.

15. An electrical oven cooking and cleaning control system as set forth in claim 14, said second thermostatically operated switch having a switch blade connectable to said one power line only when said fist switch is closed, said switch blade electrically connecting to said electrical lead when said second switch senses a temperature in said oven below a selected cooking temperature.

16. An electrical oven cooking and cleaning control system as set forth in claim 15, said first switch when closed interconnecting said one powerline to said Switchblade of said second switch and to said electrical lead.

17. An electrical oven cooking and cleaning control system as set forth in claim 16, said control means including a selector switch for opening and closing said electrical lead intermediate saidsecond switch and said first switch. 

1. An electrical oven cooking and cleaning control system comprising a bake heater, a broil heater, an electrical power source, control means having thermostatically operated switch means, and means operatively interconnecting said control means to said power source and said control means to said heaters, said switch means of said control means having a first temperaturesensing condition that interconnects said power source to said heaters for operating said bake heater at substantially full rated power and said broil heater at part rated power when said control means is set for cleaning said oven at a predetermined cleaning temperature and said oven is below said cleaning temperature, said switch means of said control means having a second temperature-sensing condition that interconnects said power source to said heaters for operating both of said bake and broil heaters at part-rated power thereof when the temperature of said oven is above said cleaning temperature.
 2. An electrical oven cooking and cleaning control system as set forth in claim 1, said switch means of said control means including a thermostatically operated switch which when closed by sensing a temperature below said cleaning temperature causes said bake heater to operate at said full-rated power and said broil heater to operate at said part rated power, said switch when opened by sensing a temperature above said cleaning temperature causing said bake and broil heaters each to operate at said part rated power thereof.
 3. An electrical oven cooking and cleaning control system as set forth in claim 2, said switch causing said bake and broil heaters to be in series relation across said power source when said switch senses a temperature above said cleaning temperature and causing said bake and broil heaters to be in parallel relation across said power source when sensing a temperature below said cleaning temperature.
 4. An electrical oven cooking and cleaning control system as set forth in claim 1, a smoke eliminator heater, means operatively interconnecting said control means to said smoke eliminator heater, said control means interconnecting said power source to said smoke eliminator heater for causing operation of said smoke eliminator heater when set in its oven-cleaning position.
 5. An electrical oven cooking and cleaning control system as set forth in claim 4, said control means interconnecting said power source to said smoke eliminator heater for causing said smoke eliminator heater to operate during a bake setting thereof and during a broil setting thereof.
 6. An electrical oven cooking and cleaning control system comprising a bake heater, a broil heater, a three wire power source comprising a neutral line and two power lines, control means having thermostatically operated switch means and means operatively interconnecting said control means to said power source and said control means to said heaters, said switch means of said control means interconnecting said bake heater across said power lines for substantially full-rated power of said bake heater when said control means is set for cleaning said oven at a predetermined cleaning temperature while interconnecting said broil heater across said neutral line and one of said power lineS for approximately one-quarter rated power of said broil heater when the temperature in said oven is below said cleaning temperature, said switch means of said control means interconnecting said bake and broil heaters in series across said neutral line and one of said power lines when the temperature in said oven is above said cleaning temperature to provide approximately one-sixteenth of the rated power of said heaters.
 7. An electrical oven cooking and cleaning control system as set forth in claim 6, said broil and bake heaters each having one side thereof electrically interconnected to said one side of the other by an electrical lead, said control means interconnecting one of said powerlines to said electrical lead when said control is set for cleaning said oven and when the temperature in said oven is below said cleaning temperature, said control means disconnecting said one power lead from said electrical lead when said control means is set for cleaning said oven and when the temperature in said oven is above said cleaning temperature.
 8. An electrical oven cooking and cleaning control system as set forth in claim 7, said control means interconnecting the other side of said broil heater to said neutral line when set for cleaning said oven and interconnecting the other side of said bake heater to the other power line when set for cleaning said oven.
 9. An electrical oven cooking and cleaning control system as set forth in claim 7, said control means interconnecting said one power line to said electrical lead when set for a bake operation and when the temperature in said oven is below the selected bake temperature, said control means interconnecting the other side of said broil heater to said neutral line and the other side of said bake heater to the other power line when set for said bake operation.
 10. An electrical oven cooking and cleaning control system as set forth in claim 7, said control means interconnecting said one powerline to said electrical lead when set for a broil operation and when the temperature in said oven is below the selected broil temperature, said control means interconnecting the other side of said broil heater to the other powerline when set for said broil operation.
 11. An electrical oven cooking and cleaning control system as set forth in claim 7, a smoke eliminator heater having one side thereof interconnected to said neutral line, said control means interconnecting the other side of said smoke eliminator heater to one of said powerlines when set for a cleaning operation.
 12. An electrical oven cooking and cleaning control system as set forth in claim 11, said control means interconnecting the other side of said smoke eliminator heater to one of said powerlines when said control means is set for a bake operation.
 13. An electrical oven cooking and cleaning control system as set forth in claim 12, said control means when set for a bake operation interconnecting the other sides of said bake and smoke eliminator heaters in parallel relation to the same powerline.
 14. An electrical oven cooking and cleaning control system as set forth in claim 7, said control means comprising a first thermostatically operated switch that interconnects said one power line to said electrical lead when said control means is set for said cleaning operation and the temperature in said oven is below said cleaning temperature, said control means comprising a second thermostatically operated switch that interconnects said one powerline to said electrical lead when said control means is set for a cooking operation and the temperature in said oven is below the selected cooking temperature, said second switch disconnecting said one powerline from said electrical lead when said control means is set for a cooking operation and the temperature in said oven is above the selected cooking temperature.
 15. An electrical oven cooking and cleaning control system as set forth in claim 14, said second thermostatically operated switch having a switch blade connectaBle to said one power line only when said fist switch is closed, said switch blade electrically connecting to said electrical lead when said second switch senses a temperature in said oven below a selected cooking temperature.
 16. An electrical oven cooking and cleaning control system as set forth in claim 15, said first switch when closed interconnecting said one powerline to said switchblade of said second switch and to said electrical lead.
 17. An electrical oven cooking and cleaning control system as set forth in claim 16, said control means including a selector switch for opening and closing said electrical lead intermediate said second switch and said first switch. 